Idle Speed/Throttle Actuator - Electronic: Testing and Inspection

Fig. 32 ISC servo test.:

1. Place ignition switch to ``Off' position, then disconnect ISC servo electrical connector, Fig. 32.
2. Check motor coil resistance, using a suitable tester, between terminals 1 and 4.ISC servo motor resistance should be 7 - 10 ohms.
3. If resistance is 0 ohm or abnormally large, motor coil is shorted or open. Replace ISC servo assembly.
4. Ensure there is no continuity between terminal 1 or 4 and injection mixer body. If continuity is present, there is a short circuit in the coil. Replace ISC servo assembly.

Fig. 30 Testing idle switch.:

1. With ISC servo connected,connect analog voltmeter between terminal 3 and injection mixer body.
2. Turn ignition off and then on. While keeping ignition on for more than 15 seconds, note the voltmeter needle. If the voltmeter indicates 11 to 13 volts with ignition on after a momentary indication of 1 volt or less, ISC servo and switch are operating normally.